Nmc cathode sinterizing drivers#
Nmc cathode sinterizing crack#

The overall performance of the cell can therefore only be enhanced by in-depth understanding of processes at the micro- and nano scale, due to the carefully designed microstructure of particles that are forming the cathode. The main bottleneck in high performance Li-ion battery cells is the cathode material, as novel Ni-rich stoichiometries with promising electrochemical properties suffer from significant degradation during the first charge and discharge cycles, which can be linked to a complex interplay of multiple transient phenomena. Broader context In order to support the growth of electrochemical energy storage applications in applications such as electric vehicles and grid scale storage, improved cathode, anode and electrolyte materials are required to unlock higher attainable charge rates in combination with enhanced energy density.

Nmc cathode sinterizing drivers#

Coupled multi-physics Finite Element Modelling of diffusion and deformation inside a single cathode particle during charge and discharge was validated by comparison with experimental evidence and allowed unequivocal identification of key mechanical drivers underlying Li-ion battery degradation. These effects were resolved in relation to the grain orientation, and the link established with the nucleation and growth of intergranular cracks and voids that causes electrical isolation of active cathode material. Preferential grain orientation within the shell of a spherical secondary cathode particle provides improved lithium transport but is also associated with spatially varying anisotropic expansion of the hexagonal unit cell in the c-axis and contraction in the a-axis. The present study is focused on sub-micron focused operando synchrotron X-ray diffraction and in situ Ptycho-Tomographic nano-scale imaging of a single nano-structured LiNi 0.8Co 0.1Mn 0.1O 2 core–shell particle during charge to obtain a thorough understanding of the anisotropic deformation and damage phenomena at a particle level.

Nmc cathode sinterizing crack#

Experimental characterisation of the transient mechanisms underlying crack and void formation requires the combination of very high resolution in space (sub-micron) and time (sub-second) domains without charge interruption. The mechanical degradation is caused by the transient lithium diffusion processes during charge and discharge of layered oxide spherical cathode micro-particles, leading to highly anisotropic incompatible strain fields. The performance and durability of Ni-rich cathode materials are controlled in no small part by their mechanical durability, as chemomechanical breakdown at the nano-scale leads to increased internal resistance and decreased storage capacity. E-mail: b Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK c Polytechnic Department of Engineering and Architecture (DPIA), University of Udine, Via delle Scienze 206, Udine, 33100, Italy d Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK e The Henry Royce Institute, Parks Road, Oxford, OX1 3PH, UK f The Faraday Institution, Quad One, Becquerel Avenue, Harwell Campus, Didcot, OX11 0RA, UK Sci., 2020, 13, 3556-3566 Synchrotron X-ray quantitative evaluation of transient deformation and damage phenomena in a single nickel-rich cathode particle †Ī a Korsunsky group, Multi-Beam Laboratory for Engineering Microscopy (MBLEM), Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK.